To improve the ease of use of scanning systems, in particular digital copiers and scanners, it is desirable to automatically detect and segment scanned objects (e.g., a hard copy document) on the platen of the input scanner. To facilitate this automated detection and segmentation, it is necessary to identify the position, shape and rotation angle of the object. Such a capability can enhance productivity by decreasing the time required for scanning documents, enable multiple images to be efficiently scanned and reduce the requirement for accurate presentation placed upon document feeding mechanisms.
The present invention is directed to a system intended to automatically determine the boundaries and overlap of multiple objects within a scanned image of a series of documents. The present invention combines a number of graphics and image processing techniques into an automated, system that provides productivity enhancement for digital copiers and scanning systems.
The present invention accomplishes these objectives by: 1) locating each of the objects within an input image; 2) modeling the shape of the identified object (e.g., rectangle); and 3) positioning the object in a digital image at a predefined locations.
Heretofore, a number of patents and publications have disclosed segmentation and detection, the relevant portions of which may be briefly summarized as follows:
U.S. Pat. No. 5,485,568 to Venable et al., issued Jan. 16, 1996, and hereby incorporated by reference, discloses a method and apparatus for representing a complex color raster image as a collection of objects in a structured image format—a hierarchical, device-independent format. A structured image document, generated using the techniques described by Venable, is a representation of data that may be rendered into a raster image. The data includes simple raster images as well as a hierarchical collection of sub-objects and raster processing operations. The possible data types for objects in the structured image include a raster image, text, graphics, image processing description, and files containing multiple image representations
U.S. Pat. No. 5,528,387 to Kelly et al., issued Jun. 18, 1996, teaches electronic image registration in a scanner. In particular, the edge data of a document is detected and skew angle calculated. The image is then rotated based upon the skew angle and non-image areas are filled using an image generation feature.
U.S. Pat. No. 4,922,350 to Rombola et al., issued May 1, 1990, discloses a two-pass scanning apparatus for detecting the size and position of an original document on a scanner platen. Image signals captured on a first scan are employed to determine boundaries and a best-fit magnification so that the image may be fit to a recording sheet using image signals generated on a subsequent scanning pass.
U.S. Pat. No. 5,253,765 to Moorehead et al, issued Oct. 19, 1993, teaches a system for sorting randomly sized objects (e.g., mushrooms). Invariant moments are employed, utilizing the complete pixel information for all pixels within the border of a captured image, to extract information about the mushroom size and orientation.
U.S. Pat. No. 5,220,398 to Horn et al. teaches an analog VLSI microchip that uses moments to determine the position and orientation of an object in a scene.
In “Invariant Fitting of Planar Objects by Primitives,” published in 1996 IEEE Proceedings of ICPR '96, pp. 508-512 Voss et al. teach a method of pattern recognition using primitives such as triangles, rectangles, circles ellipses, super-quadratics, etc. The authors further describe a technique for describing the primitives using moments in a normalized manner; resulting in a decrease in the numerical effort.
In “MANAGING AND REPRESENTING IMAGE WORKFLOW IN PREPRESS APPLICATIONS”, Technical Association of the Graphic Arts (TAGA) Vol. 1, 1995 Proceedings pp. 373-385, hereby incorporated by reference for its teachings, Venable et al. teach the use of structured images to manage workflow.
In accordance with the present invention, there is provided a method for processing multiple digital images using an imaging input device so as to reduce bleeding of edges of the multiple digital images by determining the boundaries of each of the digital images, comprising:
detecting a boundary of a first image;
detecting a boundary of a second image;
determining an overlap between the detected boundaries of the first image and second images;
calculating the overlap between the first and second images; and
modeling a third image from the calculated overlap of the first and second images wherein the third image contains at least said first and second images and represents a depiction of said first and second images without an overlap between said first and second images.
A method for processing multiple digital images using an imaging input device so as to reduce bleeding of contour edges of the multiple digital images by generating an object defined by contour edges of particular sets of the multiple digital images, comprising:
detecting a set of edges of a first object;
detecting a set of edges of a second object;
determining an overlap between the detected set of edges of the first and second objects;
calculating the overlap between the set of edges of the first and second objects; and
modeling a third object by ascertaining the calculated overlap of the first and second objects wherein the third object contains at least said first and second objects without an overlap of the set of edges of the said first and second objects.
The techniques described herein enable a user to expediently scan a document or other object, automatically recognizing the shape of the document within the digitized image, and composing a digital document incorporating the object.
The techniques described above are advantageous because they improve the efficiency of a scanning process, in the presence of severe bleeding.
The present invention will be described in connection with a preferred embodiment; however, it will be understood that there is no intent to limit the invention to the embodiments described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.